This only started happening a day or two ago, but I installed Leopard last week, so I don't think the two are connected. Basically, sometimes when I open the lid, the mouse won't work properly. It stutters and jerks all over the place. Closing all apps and such won't fix it, nor will putting it back to sleep and then waking it back up again. The only solution I've found is to restart the computer. Good thing Macs reboot so quickly! But seriously, does anyone have any ideas as to why this might be happening?